Bilateral four-part anterior fracture dislocation of
the shoulder: a case report and review of literature.

Abstract:

Although bilateral anterior dislocation of shoulder is not that
uncommon, there have been only 12 published reports on bilateral
anterior fracture dislocation of shoulder. The associated fractures have
mostly been greater tuberosity fractures with bilateral three part
fractures being reported in only two cases. To our knowledge, a
bilateral four part anterior fracture dislocation of the shoulder has
not yet been reported in the English literature. We here report a case
of bilateral anterior fracture dislocation with four part fracture of
both proximal humeri in a 60-year-old male due to electrocution.
Considering the comparatively old age of the patient and excessive
comminution of both the fractures, a bilateral hemiarthroplasty was
done. At the last follow-up after more than 2 years, the patient was
pain free with ability to comfortably carry out most of the activities
of daily life. Through our case report, we highlight the rarity of the
condition and review the available literature on the subject. We also
emphasize the importance of meticulous perioperative planning when
dealing with such cases to ensure a satisfactory long-term outcome.

The glenohumeral joint is the most frequently dislocated joint in
body with 95% dislocations being anterior, 4% posterior, and a rare
variety of inferior dislocation (luxutio erecta) seen in around 0.5% of
the cases. However, bilateral dislocations of glenohumeral joint are
relatively rare with most being posterior. (1,2) Electrocution,
epilepsy, and electroconvulsive therapy (sometimes referred to as triple
E syndrome) are frequent modes of injury in bilateral dislocations. (3)
We here report a case of bilateral anterior fracture dislocation with
four-part fracture of both proximal humeri in 60-year-old male due to
electrocution. Through our report, we emphasize the importance of
thorough physical examination of patients presenting after electrocution
even with low voltage. Such patients may complain of generalized
musculoskeletal pain due to violent muscle contractions during the
episode, but any such pain needs to be evaluated for skeletal injuries
and preferably by an orthopaedic surgeon. We also review in detail the
literature related to the subject and discuss the management options in
such patients. To our knowledge, such a presentation of bilateral
four-part anterior fracture dislocation has not yet been reported in the
English literature.

Case Report

A 60-year-old male religious teacher at a mosque got electrocuted
when he held onto metallic rails along the footsteps of the mosque while
going for his morning prayer. There had been a short circuit, which
resulted in an electric current in rails, and the patient was suddenly
thrown backward when he grabbed onto the metallic railings with both
hands. The patient felt pain in both his shoulders immediately after the
episode but never lost consciousness or developed seizures. He was taken
to a hospital where plain radiography (Fig. 1) revealed bilateral
four-part anterior fracture dislocation with striking similarity of both
sides, as if one side were a mirror image of other. There was no distal
neurovascular deficit on either side. Upon referral to our institute, a
CT scan of both shoulders (Figs. 2 and 3) was obtained that confirmed
the diagnosis of bilateral four part anterior fracture dislocation. The
CT scan showed coronal split of humeral head with comminution of
articular surface on both the sides.

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

[FIGURE 3 OMITTED]

After thorough medical evaluation and optimization of medical
status, the patient was taken for surgery and the options of both
internal fixation and hemiarthroplasty were kept. Intraoperatively 50%
of articular surface on right side and 40% on the left side was lost due
to comminution and as such no useful and stable reconstruction was
possible and a decision of bilateral bipolar hemiarthroplasty was taken.

Due to bilateral involvement and lack of adequate access to
professional trained physical therapist at home, the patient was kept in
the hospital for 1 month until he displayed satisfactory recovery of
strength and control of this shoulders. For the initial 4 weeks only,
isometric active assisted exercises were allowed without any active
flexion or abduction. On day 5, assisted external rotation exercises in
supine position were started, and then on day 8, pendulum exercises in
both internal and external rotation were added. At day 10, exercises in
standing position were allowed, and assisted hyperextension was added to
the regimen. At 2 weeks, horizontal external rotation was allowed, and
at 3 weeks, isometric exercises targeting rotations and the deltoids
(except anterior thirds) were started. As the patient progressively
regained power and control, exercises for anterior deltoids were added,
but the right side showed slight weakness for which electrical
stimulation of the anterior deltoids was administered for 1 week after
which the patient was discharged home.

[FIGURE 4 OMITTED]

The patient was followed up every month for the first 3 months,
every 3 months up until 1 year, and every 6 months thereafter. At the
last follow-up after 25 months, the patient had an excellent and pain
free range of motion in both shoulders. Radiography (Fig. 4) did not
show any signs of loosening. The active range of motion for the right
shoulder was 90[degrees] abduction, 100[degrees] flexion, 25[degrees]
extension, 25[degrees] external rotation in maximal abduction, and
30[degrees] internal rotation in maximal abduction. The active range of
motion for the left shoulder was 80[degrees] abduction, 90[degrees]
flexion, 25[degrees] extension, 25[degrees] external rotation in maximal
abduction, and 30o internal rotation in maximal abduction. Constant
score was used to evaluate the functional outcome at the last follow-up
visit and was found to be 80 for the right shoulder and 76 for the left
shoulder. The patient was able to carry out most of his previous daily
activities but had some difficulty with overhead activities due to
restriction in abduction on both sides.

Discussion

Since the first report of a bilateral dislocation of shoulder in
1902 by Mynter, (4) about 60 cases have been reported, which is a
relatively small number for over a century of literature in a joint so
vulnerable to dislocation. Although there is an overwhelming
predominance of anterior over posterior dislocations of the shoulder,
the same does not hold true for bilateral cases. Most of the bilateral
cases are posterior dislocations. (5) Bilateral anterior fracture
dislocations are still uncommon, and to our knowledge, there are only 12
published reports in the English literature. (1,2,6-15) These have been
summarized in Table 1.

The reason for relative higher frequencies of anterior or posterior
dislocations in unilateral or bilateral cases can be inferred from the
mechanisms that produce these dislocations. Anterior dislocation is
caused by the levering out of the humeral head when the greater
tuberosity impinges on the acromion in the position of extreme
abduction, extension, and external rotation. (16) This frequently occurs
in falls with outstretched arms but is rarely bilateral as one arm will
invariably hit the ground first and arms need to be relatively adducted
if a person were to land on both arms. Posterior dislocation, on the
other hand, is usually produced by indirect force of muscles with the
shoulder in an adducted and internally rotated position. (16) Thus
excessive muscle contraction in cases of electrocution, epilepsy, and
electroconvulsive therapy is a frequent cause of posterior dislocation
due to the relative strength of the internal rotators of shoulder
compared to the external rotators. (2,3) Overall, a fall or a fall after
an electric shock remain the most common cause of any type of bilateral
shoulder dislocation. (2) Apart from these usual modes of injury, a
number of unusual causes have been reported (including bilateral
anterior dislocation caused by excessive weight used during bench press
exercise (17)), but in most cases the mechanism remains the same.

Anterior glenohumeral dislocations are associated with fractures in
15% of cases, and generally, these are two part fractures involving
either the greater tuberosity or humeral neck. (18,19) Only two cases of
bilateral, three-part, anterior fracture dislocation have been described
previously. (10,15) While the mechanism of injury has not been clearly
described in one of the reports, (10) the patient in the second report
(15) was injured when a heavy object feel onto his back while he was
leaning forward holding an overhead bar; this resulted in his arms being
abducted and externally rotated. To our knowledge, bilateral, four-part,
anterior dislocation has not yet been reported in the literature. Our
case is also unique in the sense that it happens to be only the third
case of bilateral, anterior fracture dislocation due to electrocution,
(8,9) which usually causes a dislocation in opposite direction. (5)

Treatment of four-part, proximal humeral fractures presents complex
management issues due to universally poor results of nonoperative
treatment and difficulty in achieving and maintaining reduction with
internal fixation. In the series by Neer and colleagues, (20) treatment
of four-part failed in all 13 cases using internal fixation and 11 cases
treated non-operatively as opposed to one failure and 31 excellent or
satisfactory results with hemiarthroplasty. Although similar
observations have been made by other investigators, (19,21) the
treatment of proximal humeral fractures has undergone major changes in
recent years with the introduction of newer angle-stable implants, such
as locked plates. (22-24) Despite the promising results with these
implants, there are complications peculiar to plate fixation, especially
in the face of the high incidence of avascular necrosis in three- or
four-part fractures. (22,23) Late collapse of the head due to avascular
necrosis can expose screws intraarticularly and lead to rapidly
progressive arthritis. Although internal fixation remains our first
choice for difficult three- or four-part fractures in all
physiologically young patients, the relative old age of the patient and
the extreme comminution of the humeral head prevented any useful
reconstruction and forced us to perform bilateral hemiarthroplasty.

Arthroplasty for proximal humerus fractures can give reasonably
good results; though, rotator cuff tears, which occur often in cases
with fracture dislocations and tuberosity fixation, present some
technical difficulty. (25,26) However, if addressed appropriately, these
do not preclude a satisfactory result. Reports of bilateral
hemiarthroplasty for bilateral fracture dislocations of proximal humerus
are few (27,28) but have shown uniformly good results. Comminution,
large size of articular surface involvement, and poor bone quality are
the most important factors that favor arthroplasty over internal
fixation as the surgical option of choice. (28) Pain relief is the most
predictable outcome after arthroplasty, although in some cases range of
motion may be significantly restricted. However, despite the reduced
range of motion, most studies have shown more than an 80% satisfaction
rate after arthroplasty for proximal humerus fractures. (25,26,29)

To conclude, we report one of the first cases of bilateral,
four-part, anterior fracture dislocation of the shoulder. Although we
believe that angle-stable implants, such as locked plates, should be the
management modality for such patients, the presence of excessive
comminution (in such fractures) and the older age of the patient tilts
the management option in favor of hemiarthroplasty. A meticulous
perioperative evaluation goes a long way in ensuring a satisfactory
long-term outcome.

Disclosure Statement

None of the authors have a financial or proprietary interest in the
subject matter or materials discussed, including, but not limited to,
employment, consultancies, stock ownership, honoraria, and paid expert
testimony.